HOLLAND, MI -- The illness that closed Margarita’s Restaurant in Holland and caused at least 200 to become sick has been identified as norovirus, according to the Ottawa County Health Department.

Health officials are urging people to take precautions to prevent the spread of the virus, which can easily spread from person to person.

Norovirus is found in the stool and vomit of infected people, and it can be spread by touching contaminated surfaces or people and by consuming food or drinks that are contaminated, the health department says.

Alcohol-based sanitizers do not work against norovirus; it can be prevented with frequent hand-washing using soap and water and friction for 20 seconds, according to the health department.

Health officials said those with symptoms of Norovirus should not prepare food for others while they are sick, and should not prepare food for three days after symptoms end.

The health department is no longer taking reports of illness in connection to the outbreak, officials said.

About 200 people reported becoming ill since health officials began their investigation Thursday of Margarita’s Restaurant at 495 W. 17th St. Diners reported they had diarrhea, cramping, nausea, chills and vomiting, said Shannon Felgner, spokeswoman for the health department.

According to information provided by the department, norovirus is usually not serious, but it can cause people to feel very sick. There is no treatment or vaccine for the virus.

Those who are ill are advised to drink plenty of water and other fluids to prevent becoming dehydrated. Dehydration is especially a risk for the very young, the elderly, and those with weakened immune systems, and in some cases they need to see a doctor.